Composite Bladder Inflation Molding (BIM) Support
"Tackle complex hollow composite structures with confidence ..."
CSS has more than 30 years of experience supporting the design and manufacture of complex hollow FRP composite structures produced with Bladder Inflation Molding (BIM). Examples of common and more challenging BIM part geometries include:
- Tapered or Curved Tubular Structures
- Closed Envelopes; Containers, Tanks, etc.
- Hollow Rings and Annular Regions
- Hollow Hubs and Joints
- Variable (Irregular) Hollow Cross Section
CSS helps Clients design and manufacture bladder molded prototypes and production parts from prepreg layups or resin infused preforms.   Our BIM services include custom bladder design, BIM air fitting and tooling design, and BIM tailored product design and process development support.   And though CSS does not manufacture or sell bladders, we do support in-house bladder fabrication or can recommend off-the-shelf bladder solutions for straight forward applications.
CSS also supports stateside bladder molding production line start-ups via our Composite Production Support services or, in the case of medium to high volume application, overseas production and procurement of bladder molded production parts and value added assemblies (Overseas Composite Production).
Bladder Inflation Molding Advantages/Benefits ...
- Facilitates fabrication of complex hollow composite structures
- Easily combined with other composite processes; e.g. BIM and Compression Molding
- Affordable choice for high volume production of small to medium size parts
- Yields excellent OML surface quality parts
Prepreg Versus Resin Infused Dry Preforms ...
BIM parts may be fabricated using hot melt prepreg preforms or dry fiber preforms infused with resin during the bladder molding process.   The bladder's main role and internal inflation pressure often depends on the preform type.
In the case of prepreg preforms, the inflated bladder's primary role is to consolidate the pre-impregnated reinforcement layers and maintain the consolidated part shape until the resin matrix cures.   Higher positive bladder inflation pressures are typically employed to generate sufficient resin flow and to force (consolidate) the prepreg layers against the tool surface.
Prepreg Bladder Inflation Molding
A bladder for resin infusion of dry preforms, on the other hand, is typically inflated with less positive pressure or simply open to atmospheric pressure (vacuum pressure differential only) to avoid collapsing the dry fiber preform and shutting off essential resin flow channels.   The dry preform bladder's role is to contain the resin and maintain the wetted preform shape until the resin gels/cures.
Resin Infusion Bladder Inflation Molding
Bladder material selection is driven by part geometry, processing temperature, reusability requirements, and cost.   Common bladder materials include latex rubber, polyamides (nylon), silicone rubber, and polyetheretherketone (PEEK).
Bladder Inflation Molding Case Studies ...
Resin Infused Composite Spool Composite Bent Paddle Shaft Curved Composite Tent Poles Composite Stroller Frame Member
Please Contact Us to discuss your FRP composite program needs or learn more about CSS Bladder Molding Support services.